The prevention of tampering, unauthorized use, and unauthorized extraction of information from microdevices is a long standing and extensive multidisciplinary problem. The strategies of prevention can range from secrecy protection of designs and production processes of a particular microdevice to the broad area of data encryption and protected data exchange and storage. The domain of the present invention is protection of stored and structure-related information incorporated in microdevices by the physical destruction of the microdevice regions containing such information in the event that tampering, unauthorized use, and/or unauthorized extraction of such information is likely to occur. Various embodiments of the present invention include usage of high power electrical drivers that deliver sufficient electrical energy for permanent destruction of the information containing structures of protected microdevices.
Currently, the most common example of a micro-device that may need to be protected from tampering, unauthorized use, and unauthorized extraction of information is the electronic microchip also commonly known as an “integrated circuit”. Electronic microchips are ubiquitous in industrial, military, and consumer products. With this in mind, some of the presented embodiments of the invention are illustrated and evaluated using an electronic microchip as a target. However, it is important to note that the present invention is not limited to electronic devices or microchips. Apparatuses and methods in accordance with the present invention can be used to obliterate information on a variety of microdevices including, but not limited to, magnetic memory strips and media; removable memory modules and cards; security identification cards, chips, and keys; RFID tags and interrogators; MEMS; biochips; sensors; and other electronic, electro-mechanical, photonic, fluidic, chemical, and hybrid devices.
In some embodiments of the current invention, high power pulsed technology may selectively obliterate targeted information containing structures by providing a controlled high power discharge in the proximity of the information containing structures. Various embodiments of the present invention include methods and devices invented for commanded and/or self directed obliteration of the information containing structures under situations where physical control of protected microdevices may not be present, and where it is necessary to prevent hostile and/or unauthorized users from gaining and benefiting from the use of the microdevice or from the information contained in the microdevice even if they gain physical control of the protected microdevice. These embodiments usually require protection devices designed to integrate with the microdevices either permanently or as additional safety modules which, in an off or stand-by mode of operation, allow for normal function of the processing microdevices, but when activated obliterate the targeted information. Many of these embodiments can also be used to obliterate sensitive information and incompletely erased data on replaced or discarded microdevices before they are disposed or removed from the controlled environments.
An embedded load assembly arranged to localize energy dissipation, is an important element of the present Anti-Tampering (AT) technology of certain embodiments of t he current invention. One embodiment may a localized weakly resistive conductor tamped within the volume of a substrate, directly below a silicon die or any other delicate device needing AT protection. The application of a fast high voltage pulse to this conductor may cause a flow of intense currents and commensurate abrupt heating in the conductor. As the conductor heats, its resistance may increase, coupling more power from associated high voltage drivers and further h eating the conductor. This process substantially instantly (relative to the duration of the discharge) melts, vaporizer, and partially Ionizer the conductor, further producing significantly elevated pressures in the confined volume of the conductor as well as resulting intense shock waves in the substrate and relatively more delicate devices that may be mounted on it. The shock-associated pressures may exceed fracture strength of the substrate /die systems, resulting in substantially instant and thorough destruction of mounted dies and/or other protected structures.